Cross-field electron diffusion due to the coupling of drift-driven microinstabilities.

Area of Science:

• Plasma physics
• Kinetic theory
• Computational astrophysics

Background:

• Understanding plasma behavior is crucial for astrophysics and fusion energy.
• Kinetic instabilities can significantly alter plasma transport properties.
• The role of multiply charged ions in these instabilities is not fully understood.

Purpose of the Study:

• To investigate the nonlinear interaction between kinetic instabilities and magnetized electrons.
• To determine how electron diffusion across magnetic field lines is affected by coupled plasma instabilities.
• To explore the impact of multiply charged ions on plasma instabilities and transport.

Main Methods:

• A two-dimensional collisionless particle-in-cell simulation was employed.
• The simulation accounted for singly and doubly charged ions in a cross-field configuration.
• Analysis focused on nonlinear interactions and cross-field electron transport.

Main Results:

• The ion-ion two-stream instability and electron cyclotron drift instability were identified.
• These instabilities coexist and are driven by multiply charged ions.
• Coupling of these kinetic modes enhances cross-field electron transport.
• Small-scale fluctuations contribute to the broadening of ion velocity distribution functions.

Conclusions:

• The coupling of kinetic instabilities driven by multiple ion beams significantly enhances cross-field electron transport.
• Multiply charged ions play a key role in driving these instabilities.
• The findings contribute to understanding plasma transport in various astrophysical and laboratory settings.